Correction of Facial Asymmetry Using Bilateral Sagittal Split Osteotomy Combined with Anterior Mandibular Midline Split and Genioplasty

Facial asymmetry accounts for approximately two-thirds of orthognathic surgical patients and may involve discrepancies in any of the three spatial planes. Conventional bilateral sagittal split osteotomy (BSSO) has limitations in correcting patients with significant discrepancies in bilateral ramus angles. This paper proposes a novel surgical approach for the correction of facial asymmetry using BSSO combined with an anterior midline mandibular split osteotomy and genioplasty. A 30-year-old woman presented with a skeletal Class III pattern, occlusal canting, and a 3-mm deviation of the chin to the right. Intraoral examination revealed an anterior crossbite, dental midline deviation, and a left Angle’s Class III molar relationship. The additional anterior midline mandibular split osteotomy allowed expansion of the posterior transverse dimension and modification of the anterior transverse dimension. This innovative midline osteotomy enabled independent yaw rotation of the bilateral mandibular segments, resulting in improved correction of facial asymmetry compared with conventional BSSO